1. Field of the Invention
The field of the present invention is selectably operable hydraulic means for laterally shifting one end of a non-moving vehicle in order to provide a desired alignment. The present invention is particularly applicable to vehicle-mounted equipment which has an invariant lateral mounting position on the vehicle and which must be laterally aligned with a stationary workpiece axis.
2. Description of the Related Art
The use of vertically acting rigidly mounted corner cylinders, articulated arms, and the like are well known to those engaged in the art of vertically supporting vehicles mounting working equipment. Such vertical supports generally use either a screw jack or hydraulic cylinder to extend an approximately horizontal bearing plate downwardly to bear against the ground surface and thereby provide vertical support and alignment. However, while such devices are designed for providing adjustable corner vertical supports for vehicles, such devices previously have not offered any means to deal with lateral misalignment.
Accordingly, lateral alignment of the vehicle with its attendant alignment-sensitive equipment can only be achieved by repeatedly backing up and pulling forward. This procedure can be very time consuming because of the lack of ready visual feedback, since the equipment mounted on the vehicle usually obscures the field of vision of the driver. If the ground surface has soft spots and or ruts, the provision of proper alignment becomes even more difficult.
For example, truck or trailer-mounted conventional workover rigs are brought to a well location for workover operations. The driver attempts to back the workover rig so that it is centered over the wellhead. However, it can be very difficult to center the workover rig directly over the wellhead such that the driver has to pull forward and backward a number of times before the workover rig is centered over the wellhead.
A need exists for a simple, selectably operable means that can readily provide adjustments in lateral alignment for vehicles such as trucks and truck-trailer rigs. There is a need for a lateral shifting means which can be operated by one man and that does not add significant weight to the vehicle.
Furthermore, there is a need for a lateral shifting means that can be set up and retracted rapidly using rig hydraulics to facilitate proper equipment emplacement at a job site.